The present invention generally relates to a luer needle unit and an injector for medical use, and more particularly to a luer needle unit used along with a prefilled syringe, that is, a syringe having pharmaceutical liquid preliminarily filled therein and which allows setting of a disposable needle thereto, and an injector using the luer needle unit.
An injector of the aforementioned type has been constructed having various structural configuration. For example, in an injector disclosed in Japanese Utility Model Laid-Open Publication No. 2-96149 (96149/1990), a luer needle is preliminarily set to a supporting cap for supporting it fitted at a mouth of a prefilled syringe. While a needle part of the luer needle is held not to penetrate a sealing cap of the syringe before the use, a disposable needle is fixed at the outside of the luer needle and pressed together with the luer needle to the syringe at the time it is used, whereby the needle part pierces the sealing cap to allow the pharmaceutical liquid in the syringe to flow out through the needle part.
In the above construction, since it is necessary to rotate and pull out disposable needle from the syringe after the use in order to dispose of the disposable needle, in some cases, the luer needle alike is rotated and inadvertently taken out concurrently with the disposable needle. The needle part of the pulled out luer needle may hurt the fingers or the like of a user. Moreover, at the setting time of the luer needle to the supporting cap after the supporting cap is fitted at the mouth of the syringe, it may undesirably take place that the needle part of the luer needle pierces the supporting cap due to the absence of a guiding member for the needle part. Therefore, it has been difficult to set the luer needle to the supporting cap.